Free falling type rebound value measuring device and method of rebound apparatus equivalent body

Abstract

The invention relates to the technical field of standard steel anvil or sample rebound value measurement, and discloses a free falling type rebound value measuring device and method for a rebound apparatus equivalent body, and the device comprises a rack, the rebound apparatus equivalent body, a vertical rod positioning mechanism, a rebound apparatus equivalent body locking mechanism pair and a data acquisition and processing system. A dynamic force measuring platform is arranged at the bottom of a rack, a standard steel anvil or a sample is placed on the dynamic force measuring platform, vertical rod positioning mechanisms are arranged on the two sides of the standard steel anvil or the sample, a rebound apparatus equivalent locking mechanism pair is installed on the vertical rod positioning mechanisms, and a rebound apparatus equivalent is installed above the standard steel anvil or the sample through the vertical rod positioning mechanism pair. Height adjustment and locking are carried out through a rebound apparatus equivalent body locking mechanism pair, and a rebound value measuring system collects the collision and movement process of the elastic hammer and carries out data transmission and rebound value calculation. As the springback value is measured in a non-contact manner, the structure is simple, the interference is less, and the measurement result is stable and reliable, as shown in figure 1.

Description

Technical Field

[0001] The present invention relates to the technical field of standard steel anvil and sample rebound value measurement, and in particular to a free-fall type rebound value measurement device and method for a rebound hammer equivalent. Background Art

[0002] Rebound hammers are widely used for nondestructive testing of building materials and components due to their simple structure and ease of use. Currently, rebound hammers are calibrated using the component method both domestically and internationally, without a standard device for rebound value measurement. This results in inconsistent rebound values for the same specifications and models. For example, while both the commonly used M225 medium-sized rebound hammer in my country and the medium-sized rebound hammer produced by Swiss company Proceq have passed calibration, their results show systematic errors in concrete compressive strength testing. Systematic differences also exist between the test results of medium-sized rebound hammers from different domestic manufacturers.

[0003] Invented by Swiss engineer E. Schmidt in 1948, the rebound hammer is a nondestructive testing instrument for measuring the compressive strength of concrete structures or components. Its principle is to use a spring-driven hammer that strikes the concrete surface through a rod to measure the concrete rebound value. The rebound value, R, is calculated as the percentage of the instantaneous elastic deformation recovery force, which causes the hammer to rebound (X), indicated by the pointer, divided by the distance L (impact length) from the hammer to the rod before impact. This value reflects the energy lost during the impact, and the correlation between the rebound value and the concrete compressive strength can be used to estimate the concrete compressive strength of the structure or component. Due to its simple structure, ease of use, and ease of operation, as well as its nondestructive testing of structures and components, the rebound hammer is widely used in construction engineering inspections. Its unique characteristic is that the hammer does not directly strike the surface of the test object, such as a standard steel anvil or specimen. Instead, the hammer's energy is transferred to a relatively stationary standard steel anvil or specimen surface via a rod. A rebound test consists of three stages: pre-impact (drop), impact (impact), and post-impact (rebound).

[0004] Later, it was developed by reading the maximum impact velocity Vi0 and the maximum rebound velocity V of the hammer at the measuring position. r0 and the maximum impact velocity V i0 With the maximum rebound speed V r0 The Q-type rebound hammer uses the ratio of the velocity method to the rebound value as the velocity method rebound value. Although the current definition of the velocity method rebound value Q is incomplete and varies at different measurement positions, compared with the traditional displacement method rebound value R, the velocity method rebound value Q effectively avoids the influence of the friction force of the hammer driving the pointer during the impact movement of the traditional displacement method rebound value R, as well as the energy consumption caused by the friction between the various components of the rebound hammer during the rebound phase. Therefore, it can more truly reflect the physical properties of the standard steel anvil or specimen surface of the object being tested.

[0005] In 2016, the Zhejiang Institute of Metrology, in its "Research on Key Technologies and Traceability of Rebound Value Metrology," discovered that when a high-hardness mass bonded to an elastic material reaches a critical mass, the rebound value R is minimized. When the mass is below the critical mass, the rebound value R increases with decreasing mass, but the test results are unstable. When the mass is above the critical mass, the rebound value R increases with increasing mass, but the test results remain stable. Under the premise of exceeding the critical mass, the Zhejiang Institute of Metrology designed and manufactured a set of standard steel anvils (also known as rebound calibrators) for the traditional displacement method with nominal rebound values R of 20, 40, and 60. These were used to calibrate the rebound value R of rebound hammers. Because the rebound value R of the standard steel anvils is determined by averaging the measurement results of three calibrated rebound hammers from different manufacturers, the low, medium, and high rebound values R were measured to be 20.0, 39.5, and 59.9, respectively, with a good repeatability of 0.6. However, the rebound value R is still unscientific and non-unique, so the traceability of the rebound value urgently requires new metrological devices and measurement methods. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a free-fall rebound value measurement device and method for a rebound hammer equivalent, and the key technical problems to be solved are: first, non-contact measurement to improve the reproducibility and repeatability of the rebound value measurement results; second, to ensure the positive collision between the impact rod and the impact hammer, the central guide rod is vertically downward, and the friction between the central guide rod and the impact hammer is negligible, so as to minimize the interference with the impact hammer during the rebound value measurement process and improve the stability and accuracy of the rebound value measurement results; it is mainly used for the rebound value measurement and calibrating of standard steel anvils, and the physical properties testing of samples such as castings, concrete specimens, mortar specimens, bricks and paper.

[0007] In order to achieve the above-mentioned objectives, the present invention provides a free-fall rebound value measuring device of a rebound hammer equivalent, comprising a frame, a rebound hammer equivalent, a pole positioning mechanism, a rebound hammer equivalent locking mechanism pair and a data acquisition and processing system. A dynamic force measurement platform is provided at the bottom of the frame, a standard steel anvil or sample is placed on the dynamic force measurement platform, the pole positioning mechanism is on both sides of the standard steel anvil or sample, the rebound hammer equivalent locking mechanism pair is installed on the pole positioning mechanism, the standard steel anvil or sample is placed below the rebound hammer equivalent, and the height is adjusted and locked by the rebound hammer equivalent locking mechanism pair. A steel base and a foundation surface are provided on the bottom surface of the dynamic force measurement platform in sequence, and isolation grooves are provided on both sides of the steel base. The isolation grooves extend into the foundation to reduce the measurement error of the environment on the longitudinal laser interferometry measurement system and / or the transverse photoelectric measurement system. The dynamic force measurement platform collects the movement process of the impact hammer and transmits it to the data acquisition and processing system for rebound value calculation and processing.

[0008] Preferably, the rebound instrument equivalent includes a striking rod arranged on a dynamic force measuring platform, a central guide rod sleeved in the striking rod, a striking hammer, a guide flange arranged at the top end of the central guide rod, and a striking hammer release mechanism arranged on the guide flange. The striking hammer slides along the central guide rod, and a buffer spring is provided between the striking rod and the central guide rod. The striking rod, the striking hammer, the central guide rod and the center of the standard steel anvil are on the same axis.

[0009] Preferably, it also includes a longitudinal laser interferometry measurement system and / or a transverse photoelectric measurement system. A reflective film is pasted on the top surface of the impact hammer, and a light hole cooperating with the longitudinal laser interferometry measurement system is provided on the guide flange to realize longitudinal measurement of the impact of the impact hammer; the transverse photoelectric measurement system includes a lower transverse photoelectric measurement system and / or an upper transverse photoelectric measurement system. The lower transverse photoelectric measurement system is installed 1.5mm to 3.0mm above the top surface of the impact rod, and the upper transverse photoelectric measurement system is installed 1.5mm to 3.0mm above the impact rod when the impact rod and the impact hammer are in contact. 1.0mm to 2.0mm above the top surface of the hammer to achieve lateral measurement of the impact of the hammer; the vertical rod positioning mechanism is connected to the vertical rod, the top of the vertical rod passes through the frame and is fixed by the upper vertical rod fixture, and its bottom end is inserted into the frame and fixed by the lower vertical rod fixture; the rebound hammer equivalent locking mechanism pair includes an upper locking member and a lower locking member that pass through the vertical rod and are located at the upper and lower ends of the guide flange. An anti-loosening spring is provided between the rebound hammer equivalent locking mechanism pair and the guide flange to bring the hammer to the specified height and perform positioning measurement, adjustment, and confirmation of the hammer. The height H of the initial position of the hammer relative to the top surface of the rod is calculated as follows:

[0010]

[0011] Where H is the height of the initial position of the hammer relative to the top surface of the striking rod, K is the stiffness of the tension spring, L is the impact length of the tension spring, M is the mass of the hammer, and g is the gravitational acceleration at the location of the rebound value measurement device.

[0012] In order to achieve the above object, the present invention provides a method for measuring the free-fall displacement rebound value of a rebound hammer equivalent, comprising the following steps:

[0013] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0014] S2: Release the hammer release mechanism, gravity drives the hammer to hit the stationary standard steel anvil or sample surface to be tested through the hammer rod.

[0015] S3: The collision time between the hammer and the rod is collected through the dynamic force measurement platform. The data acquisition and processing system obtains the hammer movement time T between the first collision between the hammer and the rod and the second collision between the hammer and the rod. F .

[0016] S4: Calculate the height h of the maximum rebound position of the hammer relative to the top surface of the striking rod. The calculation formula is:

[0017]

[0018] Where: T F It is the hammer movement time between the first collision between the hammer and the rod and the second collision between the hammer and the rod, measured by the dynamic force measurement platform.

[0019] S5: Calculate the rebound value using the displacement method. The calculation formula is:

[0020]

[0021] Where H is the height of the initial position of the hammer relative to the top surface of the striking rod.

[0022] In order to achieve the above object, the present invention provides a method for measuring the free-fall displacement rebound value of a rebound hammer equivalent, comprising the following steps:

[0023] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0024] S2: Release the hammer release mechanism, gravity drives the hammer to hit the stationary standard steel anvil or sample surface to be tested through the hammer rod.

[0025] S3: The hammer movement time T between the first impact acceleration peak and the second impact acceleration peak measured by the longitudinal laser interferometry measurement system a , and the hammer movement time T between the first impact of the hammer and the impact rod and the second impact of the hammer and the impact rod measured by the dynamic force measurement platform F ; The measurement data of the longitudinal laser interferometry measurement system and the measurement data of the dynamic force measurement platform are mutually verified.

[0026] S4: The hammer movement time T is measured by the longitudinal laser interferometry measurement system a Based on the above, calculate the maximum rebound height h of the hammer after the hammer and the rod collide. The calculation formula is:

[0027]

[0028] Where, T a It is the hammer movement time between the first impact acceleration peak and the second impact acceleration peak measured by the longitudinal laser interferometry measurement system.

[0029] S5: Calculate the rebound value R using the displacement method. The calculation formula is:

[0030]

[0031] Where H is the height of the initial position of the hammer relative to the top surface of the striking rod.

[0032] In order to achieve the above object, the present invention provides a method for measuring the free-fall displacement rebound value of a rebound hammer equivalent, comprising the following steps:

[0033] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0034] S2: Release the hammer release mechanism, gravity drives the hammer to hit the stationary standard steel anvil or sample surface to be tested through the hammer rod.

[0035] S3: The height h of the maximum rebound position of the hammer relative to the top surface of the striking rod is directly measured by the longitudinal laser interferometry measurement system.

[0036] S4: Calculate the rebound value R using the displacement method. The calculation formula is:

[0037]

[0038] Where H is the height of the initial position of the hammer relative to the top surface of the striking rod.

[0039] In order to achieve the above object, the present invention also provides a method for measuring the free-fall velocity rebound value of a rebound hammer equivalent, comprising the following steps:

[0040] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0041] S2: Release the hammer release mechanism, gravity drives the hammer to hit the stationary standard steel anvil or sample surface to be tested through the hammer rod.

[0042] S3: Assuming that the spacing between the photoelectric point array is W, the installation height ΔH of the impact lateral photoelectric measurement system from the top surface of the impact rod is statically measured and can be determined by static measurement; measure the time ΔT when the impact hammer passes through the first photoelectric spacing W of the lateral photoelectric measurement system.

[0043] S4: Calculate the maximum impact velocity V of the hammer at the measuring position i0 , calculation formula:

[0044]

[0045] Where: V i is the average impact velocity of the hammer at the measuring position, according to the formula V i=W / ΔT calculation; where: W is the photoelectric point array spacing, ΔT is the time it takes for the hammer to pass through the first photoelectric spacing W of the lateral photoelectric measurement system, and g is the gravitational acceleration at the location of the rebound value measurement device.

[0046] S5: Calculate the maximum impact velocity V of the hammer when it hits the rod imax , calculation formula:

[0047]

[0048] Where: ΔH is the installation height of the impact transverse photoelectric measurement system from the top surface of the impact rod, g is the gravity acceleration at the location of the rebound value measurement device;

[0049] At the same time, when the impact hammer (4) hits the impact rod (3), the maximum impact speed of the impact hammer is Estimation can be performed to achieve mutual verification between the maximum impact velocity measurement results and the estimated results.

[0050] S6: The peak impact force F when the hammer strikes the rod is read through the dynamic force measurement platform. max With the impact pulse duration τ, assuming that the impact force is a half-sine wave, according to the momentum conservation theorem ∫F(t)dt=M·ΔV, the velocity method rebound value Z is calculated, and the calculation formula is:

[0051]

[0052] Where: π is the circumference of a circle, and M is the mass of the hammer (4).

[0053] In order to achieve the above object, the present invention also provides a method for measuring the free-fall velocity rebound value of a rebound hammer equivalent, comprising the following steps:

[0054] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0055] S2: Release the hammer release mechanism, gravity drives the hammer to hit the stationary standard steel anvil or sample surface to be tested through the hammer rod.

[0056] S3: The lateral photoelectric measurement system includes a lower lateral photoelectric measurement system and an upper lateral photoelectric measurement system. Assuming that the spacing between the photoelectric point array is W, the height ΔH between the lower lateral photoelectric measurement system and the top surface of the striking rod is determined by static measurement, and the time ΔT when the striking hammer passes through the first photoelectric spacing W of the lower lateral photoelectric speed measurement system is measured.

[0057] S4: Calculate the maximum impact velocity V of the hammer at the measuring position i0 , calculation formula:

[0058]

[0059] Where V i is the average impact velocity of the hammer at the measuring position, according to the formula V i =W / ΔT calculation; where: W is the photoelectric point array spacing, ΔT is the time it takes for the hammer to pass through the first photoelectric spacing W of the lower transverse photoelectric velocity measurement system; g is the gravitational acceleration at the location of the rebound value measurement device.

[0060] S5: Calculate the maximum impact velocity V of the hammer when it hits the rod imax , calculation formula:

[0061]

[0062] Where V i0 is the maximum impact velocity of the hammer at the measuring position;

[0063] At the same time, the maximum impact speed of the hammer when it hits the hammer rod can be adjusted according to the Estimation can then be performed to verify the maximum impact velocity measurement results and the estimated results.

[0064] S6: Similarly, the height Δh from the upper transverse photoelectric measurement system to the top surface of the hammer is determined by static measurement, and the time Δt when the hammer bounces through the first photoelectric distance W in the upper transverse photoelectric measurement system is measured.

[0065] S7: Calculate the maximum rebound velocity of the hammer at the measurement position. The calculation formula is:

[0066]

[0067] Where: V r is the average rebound velocity of the hammer at the measuring position, according to the formula V r =W / Δt calculation; where: W is the distance between the photoelectric point array; g is the gravitational acceleration at the location of the rebound value measurement device.

[0068] S8: Calculate the maximum rebound speed V after the hammer hits the striking rod rmax , the calculation formula is:

[0069]

[0070] S9: Calculate the rebound value Z using the velocity method. The calculation formula is:

[0071]

[0072] Where: V imax V is the maximum impact velocity when the hammer hits the rod, rmax It is the maximum rebound speed after the hammer hits the firing rod.

[0073] In order to achieve the above object, the present invention also provides a method for measuring the free-fall velocity rebound value of a rebound hammer equivalent, comprising the following steps:

[0074] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0075] S2: Release the release mechanism, gravity drives the hammer to hit the stationary standard steel anvil or sample surface to be tested through the hammer rod.

[0076] S3: Paste reflective film on the top surface of the hammer and use the longitudinal laser interferometry measurement system to directly measure the maximum impact velocity V when the hammer hits the rod. imax , the maximum rebound speed V after the hammer hits the striking rod rmax ;

[0077] At the same time, the maximum impact speed of the hammer when it hits the hammer rod can be adjusted according to the An estimate is made to verify the maximum impact velocity measurement results and the estimated results.

[0078] S4: Calculate the rebound value Z using the velocity method. The calculation formula is:

[0079]

[0080] Where: V imax V is the maximum impact velocity when the hammer hits the rod, rmax It is the maximum rebound speed after the hammer hits the firing rod.

[0081] Compared with the prior art, the present invention has the following beneficial effects:

[0082] The initial energy of the spring hammer of the present invention is obtained not from the elastic potential energy of the impact spring but from the gravitational potential energy of the spring hammer, which is simple to control, more precise and more stable; it solves the difficult problems of the friction of the pointer during the impact movement of the spring hammer in the prior art and the energy consumption due to friction between the components during the rebound movement, thereby improving the accuracy and reliability of the rebound value measurement, and can more truly represent the physical properties of the object being tested.

[0083] In order to improve the accuracy and stability of rebound value measurement, the measuring device also uses a high-precision laser interferometry system. The laser interferometry system mainly consists of a laser, a spectroscope, a receiver, etc., and uses a Bragg cell to achieve the change of velocity direction. Since the laser interferometry method can track and measure the collision and movement process of the hammer, including the maximum impact velocity V when the hammer hits the rod, imax , the maximum rebound speed V after the hammer hits the striking rod rmaxAs well as technical parameters such as the maximum rebound position of the hammer relative to the height h of the top surface of the striking rod, the accuracy of the displacement measurement and speed measurement of the hammer is improved, and the accuracy of the rebound value measurement is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Attachment Figure 1 It is a structural schematic diagram of the rebound value measuring device of the present invention;

[0085] Attachment Figure 2 This is a schematic structural diagram of Example 1 of the present invention;

[0086] Attachment Figure 3 This is a schematic structural diagram of Example 2 of the present invention;

[0087] Attachment Figure 4 This is a schematic structural diagram of Example 3 of the present invention;

[0088] Attachment Figure 5 This is a schematic structural diagram of Example 4 of the present invention;

[0089] Attachment Figure 6 This is a schematic structural diagram of Example 5 of the present invention;

[0090] Attachment Figure 7 This is a structural diagram of Example 6 of the present invention.

[0091] In the accompanying drawings: 1-data acquisition and processing system, 2-standard steel anvil or sample, 3-striking rod, 4-striking hammer, 5-reflective film, 6-center guide rod, 7-guide flange, 8-light hole, 9-striking hammer release mechanism, 10-frame, 11-upper vertical pole fixture pair, 12-longitudinal laser interferometry measurement system, 13-vertical pole positioning mechanism, 14-rebounding instrument equivalent body locking mechanism pair, 15-anti-loosening spring, 16-initial potential energy position of the hammer, 17-vertical pole, 18-maximum rebound position of the hammer, 19-lateral photoelectric measurement system, 20-dynamic force measurement platform, 21-lower vertical pole fixture, 22-steel base, 23-seismic isolation groove, 24-foundation. DETAILED DESCRIPTION

[0092] The present invention integrates optical, mechanical and electrical systems in one. The rebound hammer equivalent is composed of a striking rod 3, a striking hammer 4, a central guide rod 6, a guide flange 7 and a striking hammer release mechanism 9. The technical parameters of the striking rod 3, the striking hammer 4 and the central guide rod 6 are determined by the specifications and models of the rebound hammer and the gravity acceleration at the location of the rebound value measuring device. The initial potential energy is determined by the mass and initial position of the striking hammer 4. In view of the fact that the rebound value measurement is a binary impact system, its action process is: striking hammer 4-striking rod 3-tested object (standard steel anvil 2 or sample)-striking rod 3-striking hammer 4, which is an unstable collision system. Therefore, the size, shape and mass of the striking hammer 4 and the striking rod 5 are strictly consistent with the technical indicators of the rebound hammer of the corresponding specifications and models in the national standard GB / T9138, and the indication error is smaller, usually controlled at one-half or better of the allowable error of the national standard GB / T9138.

[0093] In view of the large mass of the frame 10 and the steel base 22 of the rebound value standard device, the frame 10 and the steel base 22 can be considered as rigid bodies in the rebound value measurement and metrological calibration of the standard steel anvil (rebound calibrator). The upper pole fixer pair 11, the pole positioning mechanism 13, and the rebound hammer equivalent locking mechanism pair 14 can adjust the height of the rebound hammer equivalent and fix it; the impact energy of the impact hammer 4 is not stored by the impact spring. Instead, it is obtained by storing energy by gravity (E=MgH), where K is the stiffness of the tension spring, L is the impact length of the tension spring; M is the mass of the impact hammer 4, g is the acceleration of gravity at the location of the rebound value measuring device, and H is the height of the initial position of the impact hammer 4 relative to the top surface of the impact rod.

[0094] The rebound value measurement of the present invention has fewer influencing factors, and the initial potential energy of the spring hammer 4 is easier to accurately determine, and the rebound value can be measured more accurately. As long as the initial position of the spring hammer 4 does not change before release, its initial energy will not change. For a specific rebound value standard device, the softer the object under test, the smaller the rebound speed; the harder the object under test, the larger the rebound speed; thus, the relationship between the rebound value and the physical properties of the object under test is clearer, and its measurement results can more truly represent the physical properties of the object under test. Figures 2-4 The specific implementation of the rebound value R of the displacement method in the present invention is further explained.

[0095] Example 1: A preferred embodiment of the present invention provides a free-fall type displacement rebound value measuring device of a rebound hammer equivalent, as shown in the attached Figure 2As shown, it includes a frame 10, a rebound hammer equivalent, a pole positioning mechanism 13, a rebound hammer equivalent locking mechanism pair 14 and a data acquisition and processing system 1. A dynamic force measurement platform 20 is provided at the bottom of the frame 10, on which a standard steel anvil 2 or a sample is placed. The pole positioning mechanism 13 is provided on both sides of the standard steel anvil 2 or the sample. The rebound hammer equivalent locking mechanism pair 14 is installed on the pole positioning mechanism 13. The rebound hammer equivalent is installed above the standard steel anvil 2 or the sample through the pole positioning mechanism 13, and is height-adjusted and locked through the rebound hammer equivalent locking mechanism pair 14. The specific details are consistent with the initial potential energy of the rebound hammer of the corresponding specification. Calculate the height of the initial position of the firing hammer 4 relative to the top surface of the firing rod 3, and perform positioning measurement, adjustment, and confirmation on the firing hammer 4.

[0096] The rebound instrument equivalent includes a rebound rod 3 arranged on a dynamic force measurement platform 20, a central guide rod 6 sleeved in the rebound rod 3, a rebound hammer 4 sliding along the central guide rod 6, a guide flange 7 is provided at the top of the central guide rod 6, a rebound hammer release mechanism 9 is provided on the guide flange 7, a buffer spring is provided between the rebound rod 3 and the central guide rod 6, the inspected object is a standard steel anvil 2 or a specimen, the rebound rod 3, the rebound hammer 4, the central guide rod 6 and the center of the standard steel anvil 2 are located on the same axis; a groove is provided on the top of the rebound hammer 4, and the rebound hammer release mechanism 9 is provided on a hook corresponding to the groove, and the hook is stuck in the groove to lock the rebound hammer 4, otherwise, the rebound hammer 4 is released; the central guide rod 6 is vertically downward, and the friction between the central guide rod 6 and the rebound hammer 4 can be ignored; at the same time, the rebound rod 3 and the rebound hammer 4 are in a center-to-center collision.

[0097] The vertical rod positioning mechanism 13 is connected to the vertical rod 17. The top end of the vertical rod 17 passes through the frame 10 and is fixed by the upper vertical rod fixer pair 11. The bottom end is inserted into the frame 10 and fixed by the lower vertical rod fixer 21. The rebound hammer equivalent locking mechanism pair 14 includes a member that passes through the vertical rod 17 and locks the upper and lower ends of the guide flange 7. An anti-loosening spring 15 is provided between the rebound hammer equivalent locking mechanism pair 14 and the guide flange 7, which keeps the hammer 4 in the initial potential energy position 16. At the same time, when the hammer 4 rebounds, the hammer 4 reaches the maximum rebound position 18. The rebound value measurement system consists of a dynamic force measurement platform 20 and a data acquisition and processing system 1. The dynamic force measurement platform 20 measures the movement of the hammer 4 and transmits it to the data acquisition and processing system 1 for rebound value calculation.

[0098] Since the rebound value of the rebound hammer is an ordinal quantity, the rebound value of the displacement method is expressed by the height h of the maximum rebound position of the hammer 4 relative to the top surface of the striking rod and the height H of the initial position of the hammer 4 relative to the top surface of the striking rod. The measurement includes the following steps:

[0099] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0100] S2: Release the hammer release mechanism 9, and gravity drives the hammer 4 to collide with the stationary standard steel anvil 2 or the sample surface to be tested through the hammer rod 3.

[0101] S3: The collision time between the hammer 4 and the rod 3 is collected by the dynamic force measurement platform 20, and the data acquisition and processing system 1 processes the collision time T between the first collision between the hammer 4 and the rod 3 and the second collision between the hammer 4 and the rod 3. F .

[0102] S4: Press Calculate the height of the maximum rebound position of the striking hammer 4 relative to the top surface of the striking rod 3.

[0103] S5: Displacement method rebound value The displacement method rebound value of the standard steel anvil 2 or the sample is calculated, processed, displayed and stored through signal electronic technology.

[0104] Example 2: A preferred embodiment of the present invention provides a free-fall type displacement rebound value measuring device of a rebound hammer equivalent, as shown in the attached Figure 3 As shown, it includes a frame 10, a rebound hammer equivalent, a pole positioning mechanism 13, a rebound hammer equivalent locking mechanism pair 14 and a data acquisition and processing system 1. A dynamic force measurement platform 20 is provided at the bottom of the frame 10, on which a standard steel anvil 2 or a sample is placed. The pole positioning mechanism 13 is provided on both sides of the standard steel anvil 2 or the sample. The rebound hammer equivalent locking mechanism pair 14 is installed on the pole positioning mechanism 13. The rebound hammer equivalent is installed above the standard steel anvil 2 or the sample through the pole positioning mechanism 13, and is height-adjusted and locked through the rebound hammer equivalent locking mechanism pair 14. The specific details are consistent with the initial potential energy of the rebound hammer of the corresponding specification. Calculate the height of the initial position of the firing hammer 4 relative to the top surface of the firing rod 3, and perform positioning measurement, adjustment, and confirmation on the firing hammer 4.

[0105] The rebound instrument equivalent includes a striking rod 3 arranged on a dynamic force measurement platform 20, a central guide rod 6 arranged in the striking rod 3, a striking hammer 4 sliding on the central guide rod 6, a guide flange 7 is provided at the top of the central guide rod 6, a striking hammer release mechanism 9 is provided on the guide flange 7, a buffer spring is provided between the striking rod 3 and the central guide rod 6, the inspected object is a standard steel anvil 2 or a specimen, the striking rod 3, the striking hammer 4, the central guide rod 6 and the center of the standard steel anvil 2 are located on the same axis; a groove is provided on the top of the striking hammer 4, and the striking hammer release mechanism 9 is provided on a hook corresponding to the groove, the hook is stuck in the groove, locking the striking hammer 4, and vice versa, releasing the striking hammer 4; the central guide rod 6 is vertically downward, and at the same time, there is a center-to-center collision between the striking rod 3 and the striking hammer 4; the friction between the central guide rod 6 and the striking hammer 4 can be ignored.

[0106] The vertical rod positioning mechanism 13 is connected to the vertical rod 17. The top end of the vertical rod 17 passes through the frame 10 and is fixed by the upper vertical rod fixer pair 11, and the bottom end is inserted into the frame 10 and fixed by the lower vertical rod fixer 21; the rebound hammer equivalent locking mechanism pair 14 includes a mechanism that passes through the vertical rod 17 and locks the upper and lower ends of the guide flange 7. An anti-loosening spring 15 is provided between the rebound hammer equivalent locking mechanism pair 14 and the guide flange 7, so that the impact hammer 4 is in the initial potential energy position 16; at the same time, when the impact hammer 4 rebounds, the impact hammer 4 is in the maximum rebound position 18.

[0107] The longitudinal laser interferometry measurement system 12 is a longitudinal (out-of-plane) acceleration laser interferometry rebound value measurement system, and a reflective film 5 is pasted on the top surface of the hammer 4. A light hole 8 is provided on the guide flange 7 to cooperate with the longitudinal laser interferometry acceleration measurement system 12 to realize the measurement of the collision and movement process of the hammer 4; the rebound value measurement system is composed of the longitudinal laser interferometry acceleration measurement system 12, the dynamic force measurement platform 20, and the data acquisition and processing system 1. The longitudinal laser interferometry acceleration measurement system 12 and the dynamic force measurement platform 20 collect data and transmit it to the data acquisition and processing system 1.

[0108] Since the rebound value of the rebound hammer is an ordinal quantity, the rebound value of the displacement method is expressed by the height h of the maximum rebound position of the hammer 4 relative to the top surface of the impact rod and the height H of the initial position of the hammer 4 relative to the top surface of the impact rod. The measurement specifically includes the following steps:

[0109] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0110] S2: Release the hammer release mechanism 9, and gravity drives the hammer 4 to slide along the central guide rod 6 and collide with the stationary standard steel anvil 2 or the sample surface to be tested through the hammer rod 3.

[0111] S3: The time T between the first impact acceleration peak and the second impact acceleration peak of the first impact hammer 4 is measured by the longitudinal laser interferometry acceleration measurement system 12. a The dynamic force measurement platform 20 measures the hammer movement time T between the first collision of the hammer 4 and the impact rod 3 and the second collision of the hammer 4 and the impact rod 3. F The longitudinal laser interferometry measurement system 12 and the dynamic force measurement platform 20 measurement data calculation results can be mutually verified.

[0112] S4: The longitudinal laser interferometry acceleration measurement system 12 measures the hammer movement time T between the first collision of the hammer 4 and the hammer rod 3 and the second collision of the hammer 4 and the hammer rod 3. a According to Calculate the maximum rebound position height of the striking hammer 4 relative to the top surface of the striking rod 3.

[0113] S5: Press The displacement method rebound value R is calculated and then processed, displayed and stored through signal electronic technology for the displacement method rebound value of the standard steel anvil 2 or the sample.

[0114] Example 3: A preferred embodiment of the present invention provides a free-fall type displacement rebound value measuring device of a rebound hammer equivalent, as shown in the attached Figure 4 As shown, it includes a frame 10, a rebound hammer equivalent, a pole positioning mechanism 13, a rebound hammer equivalent locking mechanism pair 14 and a data acquisition and processing system 1. A dynamic force measurement platform 20 is provided at the bottom of the frame 10, on which a standard steel anvil 2 or a sample is placed. The pole positioning mechanism 13 is provided on both sides of the standard steel anvil 2 or the sample. The rebound hammer equivalent locking mechanism pair 14 is installed on the pole positioning mechanism 13. The rebound hammer equivalent is installed above the standard steel anvil 2 or the sample through the pole positioning mechanism 13, and is height-adjusted and locked through the rebound hammer equivalent locking mechanism pair 14. The specific details are consistent with the initial potential energy of the rebound hammer of the corresponding specification. Calculate the height of the initial position of the firing hammer 4 relative to the top surface of the firing rod 3, and perform positioning measurement, adjustment, and confirmation on the firing hammer 4;

[0115] The rebound instrument equivalent includes a striking rod 3 arranged on a dynamic force measurement platform 20, a central guide rod 6 arranged in the striking rod 3, a striking hammer 4 sliding along the central guide rod 6, a guide flange 7 is provided at the top of the central guide rod 6, and a striking hammer release mechanism 9 is provided on the guide flange 7. A buffer spring is provided between the striking rod 3 and the central guide rod 6. The striking rod 3, the striking hammer 4, the central guide rod 6 and the center of the standard steel anvil 2 of the inspected object are located on the same axis; a groove is provided on the top of the striking hammer 4, and the striking hammer release mechanism 9 is provided on a hook corresponding to the groove. The hook is stuck in the groove to lock the striking hammer 4, and vice versa, the striking hammer 4 is released; the central guide rod 6 is vertically downward, and the friction between the central guide rod 6 and the striking hammer 4 can be ignored; the striking rod 3 and the striking hammer 4 are in a center-to-center collision.

[0116] The vertical rod positioning mechanism 13 is connected to the vertical rod 17. The top end of the vertical rod 17 passes through the frame 10 and is fixed by the upper vertical rod fixer pair 11, and the bottom end is inserted into the frame 10 and fixed by the lower vertical rod fixer 21; the rebound hammer equivalent locking mechanism pair 14 includes a pair that passes through the vertical rod 17 and locks the upper and lower ends of the guide flange 7. An anti-loosening spring 15 is provided between the rebound hammer equivalent locking mechanism pair 14 and the guide flange 7, so that the impact hammer 4 is in the initial potential energy position 16; at the same time, when the impact hammer 4 rebounds, the impact hammer 4 is in the maximum rebound position 18.

[0117] The longitudinal laser interferometry measurement system 12 is a longitudinal (out-of-plane) laser interferometry displacement measurement system. Reflective film 5 is attached to the top surface of the impact hammer 4, and a light hole 8 is provided on the guide flange 7 to cooperate with the longitudinal laser interferometry measurement system 12 to enable longitudinal displacement measurement of the impact hammer 4. The rebound value measurement system consists of the longitudinal laser interferometry measurement system 12 and the data acquisition and processing system 1. The longitudinal laser interferometry displacement measurement system 12 collects data and transmits it to the data acquisition and processing system 1 for processing.

[0118] Since the rebound value of the rebound hammer is an ordinal quantity, the rebound value of the displacement method is expressed by the height h of the maximum rebound position of the hammer 4 relative to the top surface of the striking rod and the height H of the initial position of the hammer 4 relative to the top surface of the striking rod. The measurement method includes the following steps:

[0119] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0120] S2: Release the hammer release mechanism 9, and gravity drives the hammer 4 to collide with the stationary standard steel anvil 2 or the surface of the sample to be tested through the hammer rod 3.

[0121] S3: Directly measure the height h of the maximum rebound position of the striking hammer 4 relative to the top surface of the striking rod 3 through the longitudinal laser interferometry displacement measurement system 12.

[0122] S4: Calculate the rebound value R by displacement method, according to Calculate, process, display and store the rebound value of the standard steel anvil or sample 2 by displacement method through signal electronic technology.

[0123] In the above three embodiments, the rebound value of the displacement method can be measured multiple times, and the average value and repeatability of the rebound value of the inspected object can be obtained in the end. Embodiment 1 is economical and applicable, and can be used as a measurement standard for the rebound value calibration of a standard steel anvil (also known as a rebound calibrator). As a working measuring instrument, it can be used to measure the physical properties of castings, concrete specimens, mortar specimens, bricks, paper and other specimens. Embodiments 2 and 3 use laser interferometry for measurement, which is reliable and highly accurate. They are mainly used as measurement standards for the determination and calibration of the rebound value of a standard steel anvil.

[0124] The velocity method rebound value Z defined in the present invention is different from the current velocity method rebound value Q. Specifically, the maximum rebound velocity V after the hammer 4 hits the impact rod is rmax Divide by the maximum impact velocity V when the hammer 4 hits the impact rod imax Expressed as a percentage of In addition to being used for the calibration and measurement of standard steel anvils (also known as rebound calibrators), it is also used for testing the physical properties and dynamic characteristics of castings, concrete specimens, mortar specimens, bricks, paper and other specimens. Figures 5-7The specific implementation method of the rebound value Z of the velocity method is further explained.

[0125] Example 4: A preferred embodiment of the present invention provides a free-fall velocity rebound value measuring device of a rebound hammer equivalent, as shown in the attached Figure 5 As shown, it includes a frame 10, a rebound hammer equivalent, a pole positioning mechanism 13, a rebound hammer equivalent locking mechanism pair 14 and a data acquisition and processing system 1. A dynamic force measurement platform 20 is provided at the bottom of the frame 10, on which a standard steel anvil 2 or a sample is placed. The pole positioning mechanism 13 is provided on both sides of the standard steel anvil 2 or the sample. The rebound hammer equivalent locking mechanism pair 14 is installed on the pole positioning mechanism 13. The rebound hammer equivalent is installed above the standard steel anvil 2 or the sample through the pole positioning mechanism 13, and is height-adjusted and locked through the rebound hammer equivalent locking mechanism pair 14. The specific details are consistent with the initial potential energy of the rebound hammer of the corresponding specification. Calculate the height of the initial position of the firing hammer 4 relative to the top surface of the firing rod 3, and perform positioning measurement, adjustment, and confirmation on the firing hammer 4.

[0126] The rebound instrument equivalent includes a striking rod 3 arranged on a dynamic force measurement platform 20, a central guide rod 6 arranged in the striking rod 3, a striking hammer 4 sliding along the central guide rod 6, a guide flange 7 is provided at the top of the central guide rod 6, and a striking hammer release mechanism 9 is provided on the guide flange 7. A buffer spring is provided between the striking rod 3 and the central guide rod 6. The striking rod 3, the striking hammer 4, the central guide rod 6 and the center of the standard steel anvil 2 of the inspected object are located on the same axis; a groove is provided on the top of the striking hammer 4, and the striking hammer release mechanism 9 is provided on a hook corresponding to the groove. The hook is stuck in the groove to lock the striking hammer 4, and vice versa, the striking hammer 4 is released; the central guide rod 6 is vertically downward, and the friction between the central guide rod 6 and the striking hammer 4 can be ignored; at the same time, the striking rod 3 and the striking hammer 4 are in a center-to-center collision.

[0127] The vertical rod positioning mechanism 13 is connected to the vertical rod 17. The top end of the vertical rod 17 passes through the frame 10 and is fixed by the upper vertical rod fixer pair 11, and the bottom end is inserted into the frame 10 and fixed by the lower vertical rod fixer 21; the rebound hammer equivalent locking mechanism pair 14 includes a pair that passes through the vertical rod 17 and locks the upper and lower ends of the guide flange 7. An anti-loosening spring 15 is provided between the rebound hammer equivalent locking mechanism pair 14 and the guide flange 7, so that the impact hammer 4 is in the initial potential energy position 16; at the same time, when the impact hammer 4 rebounds, the impact hammer 4 is in the maximum rebound position 18.

[0128] The lateral (in-plane) photoelectric speed measurement system 19, the lateral photoelectric measurement system 19 is installed on the vertical pole 17 and is located 1.5mm to 3.0mm above the top surface of the impact rod 3 to achieve lateral measurement of the collision condition of the impact hammer 4.

[0129] Since the rebound value of the rebound hammer is an ordinal quantity, the rebound value measurement system uses a photoelectric point array (light curtain) beam method and consists of a transverse photoelectric measurement system 19, a dynamic force measurement platform 20, and a data acquisition and processing system 1. The transverse photoelectric measurement system 19 and the dynamic force measurement platform 20 measure the motion of the hammer 4 and transmit the data to the data acquisition and processing system 1 for rebound value calculation. The measurement includes the following steps:

[0130] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0131] S2: Release the hammer release mechanism 9, and gravity drives the hammer 4 to collide with the stationary standard steel anvil 2 or the sample surface to be tested through the hammer rod 3.

[0132] S3: Assuming that the spacing between the photoelectric point array (light curtain) is W, the installation height ΔH of the impact transverse photoelectric measurement system 19 from the top surface of the impact rod 3 is measured statically; the time ΔT when the impact hammer 4 passes through the first photoelectric (light curtain) spacing W of the transverse photoelectric measurement system 19 is measured.

[0133] S4: Press V i =W / ΔT Calculate the average impact velocity V of the hammer 4 at the measurement position i ; At the same time, the maximum impact velocity of the hammer 4 at the measuring position is

[0134] S5: Press Calculate the maximum impact velocity of the hammer 4 when it strikes the rod 3; at the same time, press The maximum impact velocity of the snap hammer 4 when it strikes the snap rod 3 is estimated, and the two can be verified with each other.

[0135] S6: The peak impact force F when the hammer 4 strikes the striking rod 3 is measured by the dynamic force measurement platform 20. max and the duration of the impact pulse τ, and transmit the data to the data acquisition and processing system 1. Assuming that the impact force is a half-sine wave, according to the momentum conservation theorem ∫F(t)dt=M·ΔV, Calculates the velocity method rebound value Z. It can be used for metrological calibration of velocity method rebound values of standard steel anvils (also known as rebound calibrators). It can also be used to measure the physical properties and dynamic characteristics of castings, concrete specimens, mortar specimens, bricks, paper, etc.

[0136] Example 5: A preferred embodiment of the present invention provides a free-fall velocity rebound value measuring device of a rebound hammer equivalent, as shown in the attached Figure 6As shown, it includes a frame 10, a rebound hammer equivalent, a pole positioning mechanism 13, a rebound hammer equivalent locking mechanism pair 14 and a data acquisition and processing system 1. A dynamic force measurement platform 20 is provided at the bottom of the frame 10, on which a standard steel anvil 2 or a sample is placed. The pole positioning mechanism 13 is provided on both sides of the standard steel anvil 2 or the sample. The rebound hammer equivalent locking mechanism pair 14 is installed on the pole positioning mechanism 13. The rebound hammer equivalent is installed above the standard steel anvil 2 or the sample through the pole positioning mechanism 13, and is height-adjusted and locked through the rebound hammer equivalent locking mechanism pair 14. The specific details are consistent with the initial potential energy of the rebound hammer of the corresponding specification. Calculate the height of the initial position of the firing hammer 4 relative to the top surface of the firing rod 3, and perform positioning measurement, adjustment, and confirmation on the firing hammer 4.

[0137] The rebound instrument equivalent includes a rebound rod 3 arranged on a dynamic force measurement platform 20, a central guide rod 6 arranged in the rebound rod 3, a rebound hammer 4 sliding on the central guide rod 6, a guide flange 7 arranged at the top of the central guide rod 6, and a release mechanism 9 arranged on the guide flange 7 and locking and releasing. A buffer spring is provided between the rebound rod 3 and the central guide rod 6. The inspected object is a standard steel anvil 2 or a specimen. The centers of the rebound rod 3, the rebound hammer 4, the central guide rod 6 and the standard steel anvil 2 are located on the same axis; a groove is provided on one side of the top of the rebound hammer 4, and the rebound hammer release mechanism 9 is provided on a hook corresponding to the groove. The hook is stuck in the groove to lock the rebound hammer 4, and vice versa, the rebound hammer 4 is released; the central guide rod 6 is vertically downward, and at the same time, the rebound rod 3 and the rebound hammer 4 are in a center-to-center collision; the friction between the central guide rod 6 and the rebound hammer 4 can be ignored.

[0138] The vertical rod positioning mechanism 13 is connected to the vertical rod 17. The top end of the vertical rod 17 passes through the frame 10 and is fixed by the upper vertical rod fixer 11, and the bottom end is inserted into the frame 10 and fixed by the lower vertical rod fixer 21; the rebound hammer equivalent locking mechanism pair 14 includes a pair that passes through the vertical rod 17 and locks the upper and lower ends of the guide flange 7. An anti-loosening spring 15 is provided between the rebound hammer equivalent locking mechanism pair 14 and the guide flange 7, so that the impact hammer 4 is in the initial potential energy position 16; at the same time, when the impact hammer 4 rebounds, the impact hammer 4 is in the maximum rebound position 18.

[0139] The lateral (in-plane) photoelectric velocity measurement system 19 includes: a lower lateral photoelectric measurement system 19-1 and / or an upper lateral photoelectric measurement system 19-2. Specifically, the lower lateral photoelectric measurement system 19-1 is installed on the vertical pole 17 and is located 1.5mm to 3.0mm above the top surface of the impact rod 3, so as to achieve lateral measurement of the impact of the impact hammer 4; the upper lateral photoelectric measurement system 19-2 is installed on the vertical pole 17 and is located 1.0mm to 2.0mm above the top surface of the impact hammer when the impact rod 3 and the impact hammer 4 are in contact, so as to achieve lateral measurement of the impact rebound of the impact hammer. The rebound value measurement system is a photoelectric point array (light curtain) shooting method, which is composed of a lateral photoelectric measurement system 19, a dynamic force measurement platform 20, and a data acquisition and processing system 1. In view of the fact that the rebound value of the rebound hammer is an ordinal quantity, its measurement includes the following steps:

[0140] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0141] S2: Release the hammer release mechanism 9, and gravity drives the hammer 4 to collide with the stationary standard steel anvil 2 or the surface of the sample to be tested through the hammer rod 3.

[0142] S3: Assuming that the spacing of the photoelectric point array (light curtain) is W, the height ΔH between the lower lateral photoelectric measurement system 19-1 and the top surface of the striking rod 3 is measured statically, and the movement time ΔT of the striking hammer 4 passing through the first photoelectric (light curtain) spacing W of the lower lateral photoelectric measurement system 19-1 is.

[0143] S4: Press V i =W / ΔT Calculate the average impact velocity of the hammer 4 at the measurement position as V i , the maximum impact velocity of the hammer 4 at the measuring position

[0144] S5: Maximum impact speed when the hammer 4 hits the striking rod 3 At the same time, the maximum impact speed of the hammer 4 when it hits the impact rod 3 is Make estimates and the two can verify each other.

[0145] S6: Similarly, the height Δh between the upper transverse photoelectric measurement system 19-2 and the top surface of the hammer 4 is measured statically, and the time Δt when the hammer 4 rebounds through the first photoelectric (light curtain) spacing W of the upper transverse photoelectric measurement system 19-2 is read.

[0146] S7: Press V r =W / Δt Calculate the average rebound velocity of the hammer 4 at the measurement position as V r Then at the maximum rebound speed of the hammer 4 at the measuring position calculate.

[0147] S8: The maximum rebound speed after the hammer 4 hits the striking rod 5 is Calculate, at the same time, the maximum rebound speed when the hammer 4 hits the striking rod 3 is calculated according to Make estimates and the two can verify each other.

[0148] S9: Through the data acquisition and processing system 1, the velocity method rebound value is It is used as a measurement standard for the calibration of the rebound value using the velocity method of a standard steel anvil (also known as a rebound calibrator), and as a working measuring instrument for the physical property testing of castings, concrete specimens, mortar specimens, bricks, and paper specimens.

[0149] Example 6: A preferred embodiment of the present invention provides a free-fall velocity rebound value measuring device of a rebound hammer equivalent, as shown in the attached Figure 7 As shown, it includes a frame 10, a rebound hammer equivalent, a pole positioning mechanism 13, a rebound hammer equivalent locking mechanism pair 14 and a data acquisition and processing system 1. A dynamic force measurement platform 20 is provided at the bottom of the frame 10, on which a standard steel anvil 2 or a sample is placed. The pole positioning mechanism 13 is provided on both sides of the standard steel anvil 2 or the sample. The rebound hammer equivalent locking mechanism pair 14 is installed on the pole positioning mechanism 13. The rebound hammer equivalent is installed above the standard steel anvil 2 or the sample through the pole positioning mechanism 13, and is height-adjusted and locked through the rebound hammer equivalent locking mechanism pair 14. The specific details are consistent with the initial potential energy of the rebound hammer of the corresponding specification. Calculate the height of the initial position of the firing hammer 4 relative to the top surface of the firing rod 3, and perform positioning measurement, adjustment, and confirmation on the firing hammer 4;

[0150] The rebound tester equivalent includes a striking rod 3 provided on a dynamic force measurement platform 20, a central guide rod 6 provided in the striking rod 3, a striking hammer 4 sliding along the central guide rod 6, a guide flange 7 provided at the top of the central guide rod 6, a striking hammer release mechanism 9 provided on the guide flange 7, a buffer spring provided between the striking rod 3 and the central guide rod 6, and the striking rod 3, the striking hammer 4, the central guide rod 6 and the center of the standard steel anvil 2, which is the object to be inspected, are located on the same axis;

[0151] The vertical rod positioning mechanism 13 is connected to the vertical rod 17. The top end of the vertical rod 17 passes through the frame 10 and is fixed by the upper vertical rod fixer pair 11, and the bottom end is inserted into the frame 10 and fixed by the lower vertical rod fixer 21; the rebound hammer equivalent locking mechanism pair 14 includes a pair that passes through the vertical rod 17 and locks the upper and lower ends of the guide flange 7. An anti-loosening spring 15 is provided between the rebound hammer equivalent locking mechanism pair 14 and the guide flange 7, so that the hammer 4 reaches a specified height, that is, the initial potential energy position 16 of the hammer 4; at the same time, when the hammer 4 rebounds, the hammer 4 reaches the maximum rebound position 18.

[0152] The longitudinal laser interferometry measurement system 12 is a longitudinal (out-of-plane) laser interferometry velocity measurement system. A reflective film 5 is attached to the top surface of the impact hammer 4, and a light hole 8 is provided on the guide flange 7 to cooperate with the longitudinal laser interferometry velocity measurement system 12 to enable longitudinal velocity measurement of the impact of the impact hammer 4. The rebound value measurement system consists of the longitudinal laser interferometry velocity measurement system 12 and the data acquisition and processing system 1. The longitudinal laser interferometry velocity measurement system 12 collects data and transmits it to the data acquisition and processing system 1 for processing. Since the rebound value of the rebound hammer is an ordinal quantity, its measurement includes the following steps:

[0153] S1: Start the above-mentioned rebound value measuring device and set the relevant technical parameters.

[0154] S2: Release the hammer release mechanism 9, and gravity drives the hammer 4 to collide with the stationary standard steel anvil 2 or the surface of the sample to be tested through the hammer rod 3.

[0155] S3: Paste a reflective film 8 on the top surface of the hammer 4 and directly measure the maximum impact velocity V when the hammer 4 hits the rod using the longitudinal laser interferometry measurement system 12 imax , the maximum rebound speed V after the hammer 4 hits the striking rod rmax At the same time, the maximum rebound speed after the hammer 4 hits the impact rod 3 is Make estimates and verify each other.

[0156] S4: Through the data acquisition and processing system 1, the velocity method rebound value is Calculates, electronically processes, displays, and stores the velocity-based rebound value of a standard anvil or specimen. This is primarily used as a metrological standard for the determination and metrological calibration of velocity-based rebound values of standard anvils (also known as rebound calibrators).

[0157] In the three velocity method rebound value measurements of the above-mentioned embodiments 4 to 6, multiple measurements can be performed to finally obtain the average value and repeatability of the velocity method rebound value of the inspected object. Embodiment 4 is economical and applicable, and is mainly used for physical property testing of samples such as castings, concrete specimens, mortar specimens, bricks and paper; Embodiment 5 adopts non-contact dual-secondary photoelectric point array (light curtain) shooting technology to measure the maximum rebound velocity and maximum impact velocity of the impact hammer 4, and then calculates the velocity method rebound value, which can be used for metrological calibration of the velocity method rebound value of the standard steel anvil, and can also be used for physical property testing of samples such as castings, concrete specimens, mortar specimens, bricks and paper; Embodiment 6 uses laser interferometry to directly measure the maximum impact velocity of the impact hammer 4 during the falling process and the maximum rebound velocity during the rebound process, and calculates the velocity method rebound value. It is simple to operate, has a reliable measurement method, and is mainly used as a measurement standard for the determination and metrological calibration of the velocity method rebound value of the standard steel anvil.

[0158] In summary, as preferred, Example 1 and Example 4 are economical and applicable, and are mainly used as working measuring instruments for testing the physical properties of samples such as castings, concrete specimens, mortar specimens, bricks and paper; Example 5 is mainly used as a measurement standard for the metrological calibration of the rebound value of the standard steel anvil (also known as the rebound calibrator) by the velocity method, and can be used as a working measuring instrument for testing the physical properties of samples such as castings, concrete specimens, mortar specimens, bricks and paper.

[0159] Preferably, Examples 2, 3 and 6 adopt laser interferometry for measurement. On the one hand, the laser interferometry is used to directly measure the rebound height during the rebound process of the impact hammer 4 to calculate the rebound value R of the displacement method. On the other hand, the laser interferometry is used to directly measure the maximum impact velocity during the collision of the impact hammer 4 and the maximum rebound velocity during the rebound process to calculate the rebound value Z of the velocity method. The rebound value measurement system of Examples 2, 3 and 6 is composed of a longitudinal (out-of-plane) laser interferometry displacement or velocity or acceleration measurement system 12 and a data acquisition and processing system 1. It is simple to operate and has accurate and reliable measurements. As measurement standards, Examples 2 and 3 can be used for the determination and metrological calibration of the rebound value of the displacement method of a standard steel anvil (also known as a rebound calibrator); Example 6 can be used for the determination and metrological calibration of the rebound value of the velocity method of a standard steel anvil (also known as a rebound calibrator). Since the laser interferometry method in Example 3 directly measures the rebound displacement of the impact hammer 4, and the laser interferometry method in Example 6 directly measures the impact velocity and rebound velocity of the impact hammer 4, the measurement results are accurate and reliable, and can also be used to establish a national metrology standard for rebound values, thereby achieving scientific, accurate and unified rebound value measurement results.

[0160] The above description is only a specific embodiment of the present invention, but the technical features of the present invention are not limited thereto. Any changes or modifications made by any technician in this field within the scope of the present invention are included in the patent scope of the present invention.

Claims

1. A free-fall type rebound value measuring device of a rebound hammer equivalent, characterized in that: The invention comprises a frame (10), a rebound hammer equivalent, a vertical rod positioning mechanism (13), a rebound hammer equivalent locking mechanism pair (14) and a data acquisition and processing system (1); a dynamic force measurement platform (20) is provided at the bottom of the frame (10); a standard steel anvil (2) or a sample is placed on the dynamic force measurement platform (20); the vertical rod positioning mechanism (13) is provided on both sides of the standard steel anvil (2) or the sample; the rebound hammer equivalent locking mechanism pair (14) is installed on the vertical rod positioning mechanism (13); the rebound hammer equivalent is installed above the standard steel anvil (2) or the sample through the vertical rod positioning mechanism (13); The height is adjusted and locked by a rebound hammer equivalent locking mechanism pair (14). The bottom surface of the dynamic force measurement platform (20) is sequentially arranged on a steel base (22) and a foundation (24). Seismic isolation grooves (23) are provided on both sides of the steel base (22). The purpose of providing the seismic isolation grooves (23) is to reduce the measurement error of the longitudinal laser interferometry measurement system (12) and / or the transverse photoelectric measurement system (19) caused by the environment. The dynamic force measurement platform (20) measures the collision and movement process of the impact hammer (4) and transmits the data to the data acquisition and processing system (1) for rebound value calculation.

2. The free-fall type rebound value measuring device of a rebound hammer equivalent according to claim 1, characterized in that: The rebound instrument equivalent comprises a striking rod (3) arranged on a dynamic force measurement platform (20), a central guide rod (6) sleeved in the striking rod (3), a striking hammer (4), a guide flange (7) arranged at the top end of the central guide rod (6), and a striking hammer release mechanism (9) arranged on the guide flange (7); the striking hammer (4) slides along the central guide rod (6); a buffer spring is provided between the striking rod (3) and the central guide rod (6); the striking rod (3), the striking hammer (4), the central guide rod (6) and the center of the standard steel anvil (2) of the measured object are on the same axis.

3. A free-fall type rebound value measuring device of a rebound hammer equivalent according to claim 1 or 2, characterized in that: The invention also includes a longitudinal laser interferometry measurement system (12) and / or a transverse photoelectric measurement system (19). A reflective film (5) is pasted on the top surface of the impact hammer (4). A light hole (8) cooperating with the longitudinal laser interferometry measurement system (12) is provided on the guide flange (7) to realize longitudinal measurement of the collision and movement of the impact hammer (4). The transverse photoelectric measurement system (19) comprises a lower transverse photoelectric measurement system (19-1) and / or an upper transverse photoelectric measurement system (19-2). The lower transverse photoelectric measurement system (19-1) is installed 1.5 mm to 3.0 mm above the top surface of the impact rod (3), and the upper transverse photoelectric measurement system (19-2) is installed 1.0 mm to 2.0 mm above the top surface of the impact hammer when the impact rod (3) and the impact hammer (4) are in contact. The vertical rod positioning mechanism (13) is connected to the vertical rod (17). The top end of the vertical rod (17) passes through the frame (10) and is fixed by the upper vertical rod fixer pair (11). The bottom end of the vertical rod (17) is inserted into the frame (10) and is fixed by the lower vertical rod fixer (21). The rebound hammer equivalent locking mechanism pair (14) includes an upper locking member and a lower locking member that penetrate the vertical rod (17) and are arranged at the upper and lower ends of the guide flange (7). An anti-loosening spring (15) is provided between the rebound hammer equivalent locking mechanism pair (14) and the guide flange (7). The height of the initial position of the impact hammer (4) relative to the top surface of the impact rod (3) is H, and the impact hammer (4) is positioned, measured, adjusted and confirmed. The calculation formula is: Where: K is the stiffness of the tension spring, L is the impact length of the tension spring, M is the mass of the impact hammer (4), and g is the gravity acceleration at the location of the rebound value measurement device.

4. A method for measuring the free-fall displacement rebound value of a rebound hammer equivalent, characterized in that: The following steps are involved: S1: Start the rebound value measuring device described in claim 3 and set relevant technical parameters. S2: Release the hammer release mechanism (9), gravity drives the hammer (4) and collides with the stationary standard steel anvil (2) or the surface of the sample to be tested through the hammer rod (3). S3: The collision time between the hammer (4) and the rod (3) is measured by the dynamic force measurement platform (20). The data acquisition and processing system (1) measures the hammer movement time T between the first collision between the hammer (4) and the rod (3) and the second collision between the hammer (4) and the rod (3). F . S4: Calculate the height h of the maximum rebound position of the impact hammer (4) relative to the top surface of the impact rod (3), using the following formula: Where: T F It is the time of movement of the hammer between the first collision of the hammer (4) and the rod (3) and the second collision of the hammer (4) and the rod (3), measured by the dynamic force measurement platform (20). S5: Calculate the rebound value R using the displacement method. The calculation formula is: Wherein, H is the height of the initial position of the striking hammer (4) relative to the top surface of the striking rod (3).

5. A method for measuring the free-fall displacement rebound value of a rebound hammer equivalent, characterized in that: The following steps are involved: S1: Start the rebound value measuring device described in claim 3 and set relevant technical parameters. S2: Release the hammer release mechanism (9), gravity drives the hammer (4) and collides with the stationary standard steel anvil (2) or the surface of the sample to be tested through the hammer rod (3). S3: The time T between the first impact acceleration peak and the second impact acceleration peak of the impact hammer (4) measured by the longitudinal laser interferometry measurement system (12) a , and the time T of the hammer movement between the first collision of the hammer (4) and the hammer rod (3) and the second collision of the hammer (4) and the hammer rod (3) measured by the dynamic force measurement platform (20) F The measurement data of the longitudinal laser interferometry measurement system (12) and the measurement data of the dynamic force measurement platform (20) can be verified with each other. S4: The hammer motion time T is measured by the longitudinal laser interferometry measurement system (12) a The maximum rebound height h of the hammer after the impact of the hammer (4) and the impact rod (3) is calculated based on the following formula: Where, T a It is the time of motion of the impact hammer (4) between the first impact acceleration peak value and the second impact acceleration peak value measured by the longitudinal laser interferometry measurement system (12). S5: Calculate the rebound value R using the displacement method. The calculation formula is: Wherein, H is the height of the initial position of the striking hammer (4) relative to the top surface of the striking rod (3).

6. A method for measuring the free-fall displacement rebound value of a rebound hammer equivalent, characterized in that: The following steps are involved: S1: Start the rebound value measuring device described in claim 3 and set relevant technical parameters. S2: Release the hammer release mechanism (9), gravity drives the hammer (4) and collides with the stationary standard steel anvil (2) or the surface of the sample to be tested through the hammer rod (3). S3: Directly measure the maximum rebound position height h of the impact hammer (4) relative to the top surface of the impact rod (3) through the longitudinal laser interferometry measurement system (12). S4: Calculate the rebound value R using the displacement method. The calculation formula is: Wherein, H is the height of the initial position of the striking hammer (4) relative to the top surface of the striking rod (3).

7. A method for measuring the free-fall velocity rebound value of a rebound hammer equivalent, characterized in that: The following steps are involved: S1: Start the rebound value measuring device described in claim 3 and set relevant technical parameters. S2: Release the hammer release mechanism (9), gravity drives the hammer (4) and collides with the stationary standard steel anvil (2) or the surface of the sample to be tested through the hammer rod (3). S3: The transverse photoelectric measurement system (19) is installed 1.5 mm to 3.0 mm above the top surface of the impact rod (3). Assuming that the photoelectric array spacing is W, the installation height ΔH of the transverse photoelectric measurement system (19) from the top surface of the impact rod (3) is determined by static measurement; the time ΔT when the impact hammer (4) passes through the first photoelectric spacing W of the transverse photoelectric measurement system (19) is measured. S4: Calculate the maximum impact velocity V of the hammer (4) at the measuring position i0 , calculation formula: Where: V i is the average impact velocity of the hammer (4) at the measuring position, according to the formula V i =W / ΔT calculation; wherein: W is the photoelectric point array spacing, ΔT is the time for the impact hammer (4) to pass through the first photoelectric spacing W of the lateral photoelectric measurement system (19), and g is the gravity acceleration at the location of the rebound value measuring device. S5: Calculate the maximum impact velocity V of the hammer (4) when the hammer (4) hits the rod (3) imax , calculation formula: Where: ΔH is the installation height of the impact transverse photoelectric measurement system (19) from the top surface of the impact rod (3), g is the gravity acceleration at the location of the rebound value measurement device; At the same time, when the impact hammer (4) hits the impact rod (3), the maximum impact speed of the impact hammer is Make an estimate and realize mutual verification between the maximum impact velocity measurement results and the estimated results. S6: The peak value of the impact force when the impact hammer (4) hits the impact rod (3) is measured by the dynamic force measurement platform (20). max With the impact pulse duration τ, assuming the impact force is a half-sine wave, according to the momentum conservation theorem ∫F(t)dt=M·△V, the velocity method rebound value Z is calculated, the calculation formula is: Where: π is the circumference of a circle, and M is the mass of the hammer (4).

8. A method for measuring the free-fall velocity rebound value of a rebound hammer equivalent, characterized in that: The following steps are involved: S1: Start the rebound value measuring device described in claim 3 and set relevant technical parameters. S2: Release the hammer release mechanism (9), gravity drives the hammer (4) and collides with the stationary standard steel anvil (2) or the surface of the sample to be tested through the hammer rod (3). S3: The transverse photoelectric measurement system (19) includes a lower transverse photoelectric measurement system (19-1) and an upper transverse photoelectric measurement system (19-2). Assuming that the photoelectric point array spacing is W, the height ΔH of the lower transverse photoelectric measurement system (19-1) from the top surface of the impact rod (3) is determined by static measurement, and the time ΔT when the impact hammer (4) passes through the first photoelectric spacing W of the lower transverse photoelectric velocity measurement system (19-1) is measured. S4: Calculate the maximum impact velocity V of the hammer (4) at the measuring position i0 , calculation formula: Where V i is the average impact velocity of the hammer (4) at the measuring position, according to the formula V i =W / ΔT calculation; wherein: W is the photoelectric point array spacing, ΔT is the time for the impact hammer (4) to pass through the first photoelectric spacing W of the lower transverse photoelectric velocity measurement system (19-1); g is the gravity acceleration at the location of the rebound value measurement device. S5: Calculate the maximum impact velocity V of the hammer (4) when the hammer (4) hits the rod (3) imax , calculation formula: Where V i0 is the maximum impact velocity of the hammer (4) at the measuring position; At the same time, the maximum impact speed of the hammer (4) when it strikes the rod (3) can be adjusted according to the An estimate is made to verify the maximum impact velocity measurement results and the estimated results. S6: Similarly, the height Δh between the upper transverse photoelectric measurement system (19-2) and the top surface of the impact hammer (4) is determined by static measurement, and the time Δt for the impact hammer (4) to rebound through the first photoelectric spacing W of the upper transverse photoelectric measurement system (19-2) is measured. S7: Calculate the maximum rebound velocity of the hammer (4) at the measuring position. The calculation formula is: Where: V r is the average rebound velocity of the hammer (4) at the measuring position, according to the formula V r =W / Δt calculation; wherein: W is the photoelectric point array spacing, Δt is the time for the impact hammer (4) to rebound through the first photoelectric spacing W of the upper transverse photoelectric measurement system (19-2), and g is the gravity acceleration at the location of the rebound value measurement device. S8: Calculate the maximum rebound velocity V after the impact hammer (4) hits the impact rod (3) rmax , calculation formula: S9: Calculate the rebound value Z using the velocity method. The calculation formula is: Where: V imax V is the maximum impact velocity when the impact hammer (4) hits the impact rod (3), rmax It is the maximum rebound speed after the impact hammer (4) hits the impact rod (3).

9. A method for measuring the free-fall velocity rebound value of a rebound hammer equivalent, characterized in that: The following steps are involved: S1: Start the rebound value measuring device described in claim 3 and set relevant technical parameters. S2: Release the hammer release mechanism (9), gravity drives the hammer (4) and collides with the stationary standard steel anvil (2) or the surface of the sample to be tested through the hammer rod (3). S3: Paste a reflective film (8) on the top surface of the impact hammer (4) and directly measure the maximum impact velocity V when the impact hammer (4) hits the impact rod (3) using a longitudinal laser interferometry measurement system (12) imax , the maximum rebound speed V after the impact hammer (4) hits the impact rod (3) rmax . At the same time, the maximum impact speed of the hammer (4) when it strikes the hammer rod (3) can be adjusted according to the An estimate is made to achieve mutual verification between the maximum impact velocity measurement results and the estimated results. S4: Calculate the rebound value Z using the velocity method. The calculation formula is: Where: V imax V is the maximum impact velocity when the impact hammer (4) hits the impact rod (3), rmax It is the maximum rebound speed after the impact hammer (4) hits the impact rod (3).

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